Originally Posted by

**maxmadx** Hi, please help I am stuck on this one. I think the surface is that of a sphere or something like that but I cannot work out the above/below equation.

r(u,v) = (cos u sin v, cos u cos v, sin u)

I know that you guys dont like to just give the answers without the poster even trying, so here is what I have so far:

If the problem is: r(u,v) =(cos u sin v, cos u cos v, sinu) as above, then the non-parametric equation looks like the form:

F(x,y,z) = C where F is a function of the x,y,z coordinates defining the sphere and C is 1 so that it is completely spherical? i think... like x^2, y^2, z^2 = 1

Can anyone help make this a non-parametric equation?

edit. Actually x^2+y^2+z^2 =1 is right isnt it? But what is the algebra to derive this?

Cheers!